Lathes are widely used to cut and remove tapers from shafts, tubes, and pipes, hereinafter collectively referred to as “workpieces.” In a typical lathe, a workpiece is coupled between a chuck and a tailstock of the lathe. As the lathe rotates the workpiece, a tool post is advanced towards the chuck, removing material from the workpiece. If, however, the workpiece is not perfectly aligned between the chuck and the tailstock, then the tool post will cut a misaligned taper in the circumference of the workpiece.
To avoid this, the workpiece is first centered in the lathe. For this purpose, a tool known as a lathe center, often shortened to “center,” is employed which is mounted in the tailstock of the lathe. To center a workpiece on a lathe, a center hole is first drilled at one end of the workpiece, and secondly the center is positioned in the hole so as to rotatably mount the workpiece in the lathe. The center is particularly useful to support long workpieces where the cutting forces could deflect the workpiece excessively, reducing the finish and accuracy of the workpiece, or creating a hazardous situation. Traditionally, the center hole is drilled by removing the center from the tailstock, and installing a center drill (having a bit) in its place. The workpiece is secured into the headstock chuck, and the lathe is turned on to rotate the workpiece at a relatively low speed. The center drill is then translated toward of the workpiece until the center drill has drilled a small hole in the end of the workpiece. The center drill is then backed out of the hole, and the center drill is replaced with the center. The center is then translated toward the workpiece until the conical tip at the end of the center is positioned within the drilled hole. The workpiece is thus secured in place, correctly aligned, and ready to be turned by the lathe. Such set-up is generally cumbersome as the user (operator) has to temporarily replace the center with the center drill, and then remove the center drill to reinstall the center, resulting in excessive effort and waste of time. Furthermore, moving the tailstock around excessively increases the chance that the hole in the workpiece may be misaligned.
It is an object of the present invention to provide a center for use on a tailstock of a lathe which permits a center hole to be drilled on the lathe itself, and permits the center to be located in the drilled hole in an improved, faster, and simplified manner.